Vacuum componet 78 F250
#1
Vacuum componet 78 F250
I have a 1978 F250 with a 400. It has a componet in the vacuum system that I have not been able to identify. It sits next to the EGR valve. I have taken some pics and posted to this album: http://pg.photos.yahoo.com/ph/traxle...bum?.dir=/a2c2
The one I am talking about is the one that I have moved to the center in pic 002.
I also don't have a good pic of a vacuum diagram for the ported vac system.
I have looked at Million's diagrams and the ones on AutoZone. None of them seem to show my setup.
Can anybody identify this componet and point me to a vacuum diagram that tells how it (and other) ported system componet systems are routed?
TIA
The one I am talking about is the one that I have moved to the center in pic 002.
I also don't have a good pic of a vacuum diagram for the ported vac system.
I have looked at Million's diagrams and the ones on AutoZone. None of them seem to show my setup.
Can anybody identify this componet and point me to a vacuum diagram that tells how it (and other) ported system componet systems are routed?
TIA
#2
The thing in photo #2 is the vacuum amp. The factory calls it a Venturi Vacuum Amplifier. It controls the EGR in relationship with Venturi vacuum. If you look at it close you will see letters printed next to each port. V will go to the venturi port on the carb. M will go to manifold vacuum. R will go to the vacuum reservoir. O goes to the EGR. If you don't have a M then you possibly have a S. The S means that it has an EGR Solenoid in line with it, although I dont see an EGR solenoid in the picture. As you can see this gets very confusing and each year and engine can be completly different. As to getting a decent vacuum diagram, good luck. I was fortunate on mine because I had a smog machine at the time and made copies of my trucks vacuum diagrams before I sold the smog station. You might make friends with a smog mech and see if he will show you his books. They were pretty complete at the time I was doing smogs. If I can be any Help I will be glad to try. Give me more info and I will try to help. Good luck
#3
Thanks!
I have added a picture to the album with the VVA removed. It includes what I assume to be a solenoid but I am not sure because I am used to electrical solenoids. In the picture I have identified the different ports and what markings they have. The line that goes to the 's' port on the back of the VVA has a yellow tag. The one that goes to the 'v' port has a blue tag. The one that is marked 'o' goes to the solenoid and then to the EGR valve. The port marked 'r' goes to the resivoir. I have noted that the 'v' goes to the back of the carb (Autolite 2150). The 's' goes to a tee that goes to the carb on the choke side and to the top port on the front PVS. I don't know if the inline can shaped one way valve is in the right place. I noticed that it says 'DIST' on the white side.
I can't say for sure that this is hooked up the way it should be. I have owned the vehicle since 1981 and I had a rebuilt 400 ci engine installed by a friend in about 1989. Other than that I am the only one who has ever worked on it. I have long been bothered by some irritating problems that I attribute to vacuum routing but I never have found a good source of information so I have been living with it. The problem is that, after it warms up, it does not idle smoothly. I have also noticed that it will not kick back out of 2nd gear when I let off the accelerator after flooring it. I want to get these things smoothed out soon because I plan on selling it and I hate to take a hit on the price when the problem is so small.
I appreciate any advice you can give me.
I have added a picture to the album with the VVA removed. It includes what I assume to be a solenoid but I am not sure because I am used to electrical solenoids. In the picture I have identified the different ports and what markings they have. The line that goes to the 's' port on the back of the VVA has a yellow tag. The one that goes to the 'v' port has a blue tag. The one that is marked 'o' goes to the solenoid and then to the EGR valve. The port marked 'r' goes to the resivoir. I have noted that the 'v' goes to the back of the carb (Autolite 2150). The 's' goes to a tee that goes to the carb on the choke side and to the top port on the front PVS. I don't know if the inline can shaped one way valve is in the right place. I noticed that it says 'DIST' on the white side.
I can't say for sure that this is hooked up the way it should be. I have owned the vehicle since 1981 and I had a rebuilt 400 ci engine installed by a friend in about 1989. Other than that I am the only one who has ever worked on it. I have long been bothered by some irritating problems that I attribute to vacuum routing but I never have found a good source of information so I have been living with it. The problem is that, after it warms up, it does not idle smoothly. I have also noticed that it will not kick back out of 2nd gear when I let off the accelerator after flooring it. I want to get these things smoothed out soon because I plan on selling it and I hate to take a hit on the price when the problem is so small.
I appreciate any advice you can give me.
#4
In this sentence: "I don't know if the inline can shaped one way valve is in the right place. I noticed that it says 'DIST' on the white side." I mean the can-shaped, inline black and white valve that is on the blue-tagged 'v' hose.
Here is the link to the pic's again: http://pg.photos.yahoo.com/ph/traxle...bum?.dir=/a2c2
The added pic is the one named "F250 VVA and controls"
Here is the link to the pic's again: http://pg.photos.yahoo.com/ph/traxle...bum?.dir=/a2c2
The added pic is the one named "F250 VVA and controls"
#5
That item that you think is the solenoid appears to be a vacuum resistor. I hate to tell you this but I don't remember anything but the 460 having a vacuum amplifier. The mount studs for the amp are on the valve cover and I don't see any. Usually the 400 has the vacuum resistor going thru a pvs. This thing seems all wrong. You are going to have to find a vacuum diagram that is specific to this vehicle. A visit to a smog mech might be in order. if I get any more info I will be glad to pass it on. Good Luck Gary
#7
Thanks Gary.
I am sure that it is a 400. As I said, I got it in 1981 with about 50,000 miles and when I got the new rebuilt engine, I insisted that he get a 400 and not a 351. It is possible that the guy who exchanged the engine got things hooked up wrong. Come to think of it, that is when I started noticing little problems. It took me a while to figure out that it was probably in the vac routing.
If it is possible to take the amplifier out of the system, I would go for that too. I just need a diagram for where everything should go to make it run right. It has a c6 transmission and a Dana 61 3:07 rear end if that helps any.
If anybody else has any ideas, please chime in.
I am sure that it is a 400. As I said, I got it in 1981 with about 50,000 miles and when I got the new rebuilt engine, I insisted that he get a 400 and not a 351. It is possible that the guy who exchanged the engine got things hooked up wrong. Come to think of it, that is when I started noticing little problems. It took me a while to figure out that it was probably in the vac routing.
If it is possible to take the amplifier out of the system, I would go for that too. I just need a diagram for where everything should go to make it run right. It has a c6 transmission and a Dana 61 3:07 rear end if that helps any.
If anybody else has any ideas, please chime in.
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#8
Thanks Million. We were posting at the same time. I had visited the website at "Dennis' Motorworks webpage" and looked around. I found different pics there of a 351/400 but not any schematics like the one you posted. I saw some of those on the AZ site but I couldn't figure out what was what. They didn't have any index to tell you what the abbreviations meant. I see that the other address is ford-trucks.com. I will have a look.
#9
Just click my user name to get to my gallery.
I'll post the abbrv's as well.
http://www.clubfte.com/users/mil1ion...mDiagrams.html
Emission diagrams aren't going to be differnt because of
Engine
Trans
Rear gear ratio
Altitude of operation
Each engine comes with a Calibration code Sticker on the pass side valve cover.
That's what determines,all the settings & the way the lines are hooked up
I'll post the abbrv's as well.
http://www.clubfte.com/users/mil1ion...mDiagrams.html
Emission diagrams aren't going to be differnt because of
Engine
Trans
Rear gear ratio
Altitude of operation
Each engine comes with a Calibration code Sticker on the pass side valve cover.
That's what determines,all the settings & the way the lines are hooked up
Last edited by Mil1ion; 05-21-2005 at 12:06 AM.
#10
Million said:
"Each engine comes with a Calibration code Sticker on the pass side valve cover.
That's what determines,all the settings & the way the lines are hooked up ."
The sticker on my valve cover is still in good shape but it is on the driver's side. Can I use that info to change the routing of the vacuum lines?
Bill
"Each engine comes with a Calibration code Sticker on the pass side valve cover.
That's what determines,all the settings & the way the lines are hooked up ."
The sticker on my valve cover is still in good shape but it is on the driver's side. Can I use that info to change the routing of the vacuum lines?
Bill
#11
Calibration Code Sticker
The sticker on the valve cover says:
Engine Family 351M/400 EGR
Displacement 6.6L (400 cid)
Spark Plug ASF-42 Gap .042-.046
It has a chart with some setting info on idle and kick down etc. Then it says:
NON CATALYST
D8TE-9C485-ACA D009
This engine conforms to U.S. Environmental Protection Agency Regulations Applicable to 1978 model year gasoline fueled Heavy Duty.
Since it is a non-catalyst, isn't it possible to simplify the vacuum routing?
Since the vehicle is over 24 years old, my State does not require smog testing on it.
Engine Family 351M/400 EGR
Displacement 6.6L (400 cid)
Spark Plug ASF-42 Gap .042-.046
It has a chart with some setting info on idle and kick down etc. Then it says:
NON CATALYST
D8TE-9C485-ACA D009
This engine conforms to U.S. Environmental Protection Agency Regulations Applicable to 1978 model year gasoline fueled Heavy Duty.
Since it is a non-catalyst, isn't it possible to simplify the vacuum routing?
Since the vehicle is over 24 years old, my State does not require smog testing on it.
#12
#13
That's not the calibration sticker.
That's the engine ID label
This is the calibration sticker (label)
The code for this engine that the sticker respresents is:
80-93J-RO
& these are your settings.
http://www.clubfte.com/users/mil1ion...tionSpecs2.JPG
Now you just need a diagram for the routing.
Yours should be in here,
http://www.clubfte.com/users/mil1ion...ationCodes.JPG
From what I know your's should be: 7-74-R10
That's the engine ID label
This is the calibration sticker (label)
The code for this engine that the sticker respresents is:
80-93J-RO
& these are your settings.
http://www.clubfte.com/users/mil1ion...tionSpecs2.JPG
Now you just need a diagram for the routing.
Yours should be in here,
http://www.clubfte.com/users/mil1ion...ationCodes.JPG
From what I know your's should be: 7-74-R10
Last edited by Mil1ion; 05-21-2005 at 09:24 PM.
#14
Yea Million,
Mine is a 7-74-R10. And the calibration specs are on the sticker I mentioned. They are in that part where it says "setting info on idle, kickdown, etc." I know enough to figure out where to set the idle and such. I just don't know how to route the LCV, VCV, VVA, and EGR. And I still don't know if I even need a VVA and, if I don't, how to route everything so that it runs better than now. There are things in the 351/400 diagram that you referenced here: http://www.clubfte.com/users/mil1ion...mDiagrams.html
that I don't have (like the air bypass valve) that hook up to the VDV. Also, I am confused about the VCV's in the diagram in your post. Is a VCV the same thing as a PVS (ported vacuum switch)? If so, the ones on my engine have only three outlets each where the ones in your drawing have 4 and 2 respectively.
Ahh, I just went looking for a confused emoticon and I realized that they are not available in the quick post. So, ....confused....
Mine is a 7-74-R10. And the calibration specs are on the sticker I mentioned. They are in that part where it says "setting info on idle, kickdown, etc." I know enough to figure out where to set the idle and such. I just don't know how to route the LCV, VCV, VVA, and EGR. And I still don't know if I even need a VVA and, if I don't, how to route everything so that it runs better than now. There are things in the 351/400 diagram that you referenced here: http://www.clubfte.com/users/mil1ion...mDiagrams.html
that I don't have (like the air bypass valve) that hook up to the VDV. Also, I am confused about the VCV's in the diagram in your post. Is a VCV the same thing as a PVS (ported vacuum switch)? If so, the ones on my engine have only three outlets each where the ones in your drawing have 4 and 2 respectively.
Ahh, I just went looking for a confused emoticon and I realized that they are not available in the quick post. So, ....confused....